Satellite cell proliferation in adult skeletal muscle

Abstract

Novel methods of retroviral-mediated gene transfer for the in vivo corporation and stable expression of eukaryotic or prokaryotic foreign genes in tissues of living animals is described. More specifically, methods of incorporating foreign genes into mitotically active cells are disclosed. The constitutive and stable expression of E. coli beta -galactosidase gene under the promoter control of the Moloney murine leukemia virus long terminal repeat is employed as a particularly preferred embodiment, by way of example, establishes the model upon which the incorporation of a foreign gene into a mitotically-active living eukaryotic tissue is based. Use of the described methods in therapeutic treatments for genetic diseases, such as those muscular degenerative diseases, is also presented. In muscle tissue, the described processes result in genetically-altered satellite cells which proliferate daughter myoblasts which preferentially fuse to form a single undamaged muscle fiber replacing damaged muscle tissue in a treated animal. The retroviral vector, by way of example, includes a dystrophin gene construct for use in treating muscular dystrophy. The present invention also comprises an experimental model utilizable in the study of the physiological regulation of skeletal muscle gene expression in intact animals.

What is claimed is: 
     
       1. A method for enhancing incorporation of a foreign gene into a tissue and expressing the incorporated foreign gene comprising: inducing a mitotically-active state in a tissue in vivo to provide tissue with enhanced receptivity to the incorporation of a foreign gene;   preparing a retroviral vector capable of infecting a eucaryotic stem cell, said vector comprising a foreign gene; and   injecting the tissue in vivo with the retroviral vector; wherein said method results in incorporation and expression of the gene.     
     
     
       2. The method of claim 1, wherein the retroviral vector comprises a eucaryotic foreign gene. 
     
     
       3. The method of claim 1, wherein the foreign is a prokaryotic gene. 
     
     
       4. The method of claim 3, wherein the prokaryotic gene is a β-galactosidase gene. 
     
     
       5. The method of claim 1, wherein the foreign gene is a eucaryotic gene within a replication defective retroviral vector. 
     
     
       6. The method of claim 1 wherein a mitotically active state in a tissue is induced by treating the tissue with estrogen. 
     
     
       7. A method of retroviral injection into a tissue for the incorporation of a gene in a tissue comprising: injecting the tissue with bupivacaine to induce a mitotically active state; and   injecting the mitotically active tissue with a retroviral vector including the gene; wherein said method provides efficient incorporation of the gene in the tissue.     
     
     
       8. The method of claim 7 wherein the tissue is muscle tissue. 
     
     
       9. The method of claim 7 wherein the tissue is uterine tissue. 
     
     
       10. The method of claim 7 wherein the retroviral vector is replication defective. 
     
     
       11. The method of claim 10 wherein the retroviral vector is a murine leukemia virus. 
     
     
       12. The method of claim 11 wherein the murine leukemia virus is Moloney murine leukemia virus. 
     
     
       13. The method of claim 7 wherein the foreign gene is a β-galactosidase gene. 
     
     
       14. A method for incorporating and expressing a foreign gene in a tissue comprising: inducing a mitotically-active state in a tissue in vivo; and injecting the tissue in vivo with a retroviral vector, said retroviral vector including a foreign gene, wherein said foreign gene is efficiently incorporated in vivo in the tissue.